Tools and Materials for Building an AR

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Short Story: You cannot build an AR (period) without certain tools. You cannot build an AR properly without the appropriate tools and lubrication.

If you are starting from scratch, you are looking at a minimum $350 investment for the necessary tools and materials. But it is an investment that will give you the capability to maintain and repair your firearm, as well as build as many of these as you want (WARNING: building ARs is addictive…the cost of DIY can balloon very quickly 😉). After all, you typically only need to buy a tool once.

R: Required

r: Recommended

O: Optional

Slick Stuff and Sticky Stuff (Lubrication and Thread Locker)

Check out the Lock and Lube page for details about how to use lubricants and thread locker.

What It Is	Why You Need It	Part Number	PB Pick
High Temp Grease (r)	Installation of the barrel nut and castle nut.	AG33MS	AeroShell 64/33 MS Grease
High Temp Grease (r)	Installation of the barrel nut and castle nut.	TW25B	Mil-Comm TW25B Grease
Ultra High Temp Grease (r)	Anti-seize paste for installation of muzzle device.	Molykote	Molykote G Rapid Plus Paste
Wet Lubricant (R)	Lubrication of moving parts in high wear areas. Custom blend is great for long term storage and heavy usage.	CustomLube	Custom Blend Lubricant
Wet Lubricant (R)	Lubrication of all moving parts. Synthetic oil stays in place in all conditions.	Mobil1	Mobil 1 Full Synthetic Oil
Wet Lubricant (R)	Lubrication of all moving parts. If you use CLP, you must relubricate frequently. Not for long term storage.	Clenzoil	Clenzoil Field and Range CLP Lubricant
Dropper Bottle	For applying custom blend wet lube.	DropperBottle	Dropper Bottle
Needle Bottle	For applying oil or CLP in tight spaces. Without one of these, you are very likely to overlubricate.	Needle-Bottle	Needle Bottle
Thread Locker	For gas block set screws.	Rocksett	Flexbar Rocksett Thread Locker
Thread Locker	Only use for your muzzle device if the manufacturer recommends thread locker.*	RocksettMA	Flexbar Rocksett Muzzle Adhesive

* Please PLEASE read the Lock and Lube page before you apply any type of thread locker to any part of your AR.

Tools For Leverage (Wrenches)

What It Is	Why You Need It	Part Number	PB Pick
Aero Precision Enhanced Barrel Nut Wrench (R)	Installation or removal of the barrel nut on an Aero Precision M4E1 upper. THIS IS INCLUDED with Aero Precision Enhanced upper receivers.	APRH100394C	Aero Precision M4E1 Barrel Nut Wrench
Free Float Barrel Nut Wrench (R)	Installation or removal of the barrel nut for a free float handguard.	AVMFFFBNW	Real Avid Free Float Barrel Nut Wrench
Delta Ring Barrel Nut Wrench (R)	Installation or removal of a mil-spec barrel nut.	AVMFDRBNW	Real Avid Delta Ring Barrel Nut Wrench
5/8" Muzzle Device Wrench (R*)	Used to tighten muzzle devices with 5/8" wrench flats and A2 receiver extensions.*	AVMF58MDW	Real Avid 5/8" Muzzle Device Wrench
3/4" Muzzle Device Wrench (R*)	Used to tighten muzzle devices with 3/4" wrench flats.*	AVMF34MDW	Real Avid 3/4" Muzzle Device Wrench
3-Prong Muzzle Device Wrench (R*)	Used to tighten 3-prong muzzle devices.*	AVMF3PFHW	Real Avid 3-Prong Flash Hider Wrench
Adjustable Crowfoot Wrench (R*)	Used to tighten muzzle devices that do not have standard wrench flats.*	AVMFAW	Real Avid Adjustable Crowfoot Wrench
AR-15 Armorer's Wrench (O**)	Used to tighten various fittings.	MI-ARAW	Midwest Industries Professional Armorer's Wrench
AR-15 Armorer's Wrench (O**)	Used to tighten various fittings.	AVAR15AMW	Real Avid Master Armorer's Wrench
Torque Wrench, 35-65 ft. lb, 1/2" Drive (R)	Torqueing the barrel nut and castle nut. We've fallen in love with digital torque wrenches, so we have to recommend this one.	64916	Quinn Digital Torque Wrench, 1/2", 12.5-250 ft. lb
Torque Wrench, 35-65 ft. lb, 1/2" Drive (R)	Torqueing the barrel nut and castle nut. If you don't want digital, this one works great.	24335	TEKTON Torque Wrench, 1/2", 10-150 ft. lb
Breaker Bar, 1/2" Drive (r)	Loosening torqued components. You should NOT use a torque wrench for this task. It can cause damage to the torque drive. We also use this for exercising the threads of the castle nut and barrel nut before torqueing.	00211A	Neiko Breaker Bar, 1/2" Drive, 18"

* Muzzle devices may require specific torque (refer to the muzzle device manufacturer’s instructions) and therefore, the wrench should be compatible with your torque wrench. If you are using a crush washer, you probably don’t need to torque the muzzle device (see the Muzzle Device installation section for more details). If you choose to not use a purpose-built wrench, we strongly recommend a fixed crescent wrench versus an adjustable wrench to avoid damaging the the muzzle device. Check the specifications of your muzzle device for the need for a wrench and, if so, the span of the wrench flats. Be aware that some muzzle devices include a spanner wrench (e.g. Precision Armament Hypertap Muzzle Brake). The 5/8″ wrench that we like is compatible with muzzle devices that have 5/8″ wrench flats (common for 1/2-28 muzzle devices). Similarly, the 3/4″ wrench is compatible with muzzle devices that have 3/4″ wrench flats (common for 5/8-24 muzzle devices).

** If you are using an armorer’s wrench in place of any other wrench, be sure the wrench has a 1/2″ socket for a torque wrench. Consult our Torque Adjustment page for instructions on calculating the adjusted torque setting for your tool.

Tools You Twist (Drivers and Bits)

What It Is	Why You Need It	Part Number	PB Pick
T-Handle Hex Driver (R)	Use with torque bits to torque small screws.	FISTHandle	Fix It Sticks Ratcheting T-Handle
Torque Bit, 20 in. lb (R)	Torqueing gas block set screws.	FIS20	Fix It Sticks 20 in. lb Torque Limiter
Torque Bit, 25 in. lb (R)	Torqueing Aero Precision Enhanced Handguard screws.	FIS25	Fix It Sticks 25 in. lb Torque Limiter
Torque Wrench Driver, 15-40 in. lb (R)	This is a great all around torque driver and is an alternative to torque bits (especially if you are not building guns for a living). Use it for torqueing the gas block set screws, handguard screws, and optic/scope mount screws.	553556	Wheeler F.A.T. Torque Driver
SAE Hex Key Set, Good (R)	Tightening and loosening various screws and bolts. You will need 1/16″ through 3/16″.	18CMSHKS-2DB	Lichamp 18-Piece Long Allen Wrench Set
SAE Hex Key Set, Better (R)	Tightening and loosening various screws and bolts. You will need 1/16″ through 3/16″.	‎212ZH12CN	PB Swiss 12-Piece Allen Wrench Set
Screwdriver Set, Good (r¹)	Prying, screwing, etc.	‎LTK044	Amazon Basics 12-Piece Magnetic Screwdriver Set
Screwdriver Set, Better (r¹)	Prying, screwing, etc.	GRHG8	Grace USA 8-Piece Screwdriver Set
Screwdriver Set, Best (r¹)	Prying, screwing, etc.	1201	Forster 8-Piece Screwdriver Set
Long Reach 3/32″ Ball Head Hex Driver (r)	For adjusting Superlative Arms adjustable gas blocks without removing the handguard.	10605	Bondhus Extra Long 3/32" Hex Driver
Long Reach 7/64″ Ball Head Hex Driver (r)	For adjusting Odin Works adjustable gas blocks without removing the handguard.	3706	Bondhus Extra Long 7/64" Hex Driver

* Only required for installing the buttstock mounting screw for rifles.

Tools You Whack (Punches)

What It Is	Why You Need It	Part Number	PB Pick
Center Punch (R)	Staking the receiver end plate/receiver extension castle nut. We use a spring loaded punch to start the stake.	18C	Starrett Automatic Center Punch
Center Punch (R)	Staking the receiver end plate/receiver extension castle nut. We use this tool to finish the stake. It delivers massive amounts of force with little effort and little risk of deforming the buffer tube.	28R45-1	Spring Tools Center Punch
Center Punch (R)	Staking the receiver end plate/receiver extension castle nut. If you prefer a hammer and punch, this is your best bet.	264E	Starrett Steel Center Punch
Steel Pin Punch (R)	Driving roll pins.	IRHT82531	Irwin 6-Piece Steel Punch Set
Brass Pin Punch (r)	Non-marring punch for “helping” stubborn pins along.	SW-66008	Swanlake 8-Piece Brass Punch Set
5/64″ Roll Pin Starter Punch (R)	Installing the gas tube roll pin to attach the gas tube to the gas block. Reassembling the charging handle after disassembly (UNCOMMON).	OA-APS-15-12	Obsidian Arms 12 Piece Roll Pin Punch Set
5/64″ Roll Pin Finish Punch (R)	Installing the gas tube roll pin to attach the gas tube to the gas block. Disassembling and reassembling the charging handle (UNCOMMON).	OA-APS-15-12	Obsidian Arms 12 Piece Roll Pin Punch Set
1/16″ Roll Pin Starter Punch (O¹)	Removing and reinstalling the ejector on the bolt carrier group.¹	OA-APS-15-12	Obsidian Arms 12 Piece Roll Pin Punch Set
1/16″ Roll Pin Finish Punch (O¹)	Removing and reinstalling the ejector on the bolt carrier group.¹	OA-APS-15-12	Obsidian Arms 12 Piece Roll Pin Punch Set
3/32″ Roll Pin Starter Punch (O²⋅³)	Installing the bolt catch roll pin to attach the bolt catch to the lower receiver.² Installing the forward assist assembly onto the upper receiver³ and disassembling the forward assist assembly (UNCOMMON).	OA-APS-15-12	Obsidian Arms 12 Piece Roll Pin Punch Set
3/32″ Roll Pin Finish Punch (O²⋅³)	Installing the bolt catch roll pin to attach the bolt catch to the lower receiver.² Installing the forward assist assembly onto the upper receiver³ and disassembling the forward assist assembly (UNCOMMON).	OA-APS-15-12	Obsidian Arms 12 Piece Roll Pin Punch Set
1/8″ Roll Pin Starter Punch (O⁴)	Installing the trigger guard onto the lower receiver.⁴	OA-APS-15-12	Obsidian Arms 12 Piece Roll Pin Punch Set
1/8″ Roll Pin Finish Punch (O⁴)	Installing the trigger guard onto the lower receiver.⁴	OA-APS-15-12	Obsidian Arms 12 Piece Roll Pin Punch Set

1: Generally not required unless you buy the BCG unassembled or need to replace the ejector.

2: Not required for Aero Precision Enhanced Lower Receivers, which have a threaded screw in place of the roll pin. Anyone who has attempted to seat a bolt catch roll pin for the first time can tell you (and probably show you via the marred lower receiver) how much of a blessing this feature is.

3: Not required for Aero Precision Enhanced Upper Receivers, which have a threaded screw in place of the roll pin.

4: Not required for Aero Precision Enhanced Lower Receivers, which have the trigger guard forged onto the lower receiver.

Tools You Swing (Hammers and Mallets)

1: Brass is best, but any metal head will work. We recommend something 8oz or less.

Tools That Hold Stuff (Blocks and Vices)

What It Is	Why You Need It	Part Number	PB Pick
Bench Vice (R¹)	You cannot properly torque a barrel nut or receiver extension castle nut without a solid bench vice.¹	LV-4	Yost Vices LV-4
Vice Jaws (r)	Use these if you need to secure the firearm directly in the vice.	‎W004708	WORKPRO 4 1/2" Vice Jaw Pads (2 sets)
Lower Receiver Vice Block (r²)	The best way to secure your lower receiver while you torque and stake your castle nut. Helps secure the lower receiver while you install the lower receiver parts.²	05-314	Geissele Reaction Block
Lower Receiver Vice Block (r²)	The best way to secure your lower receiver while you torque and stake your castle nut. Helps secure the lower receiver while you install the lower receiver parts.² If you don't want to drop $200 on the Geissele, this is a great alternative.	VTARLWRVB	Vism AR Lower Vice Block
Upper Receiver Action Rod, AR-15 (R)	The only way to properly secure your upper receiver while you install your barrel and muzzle device.	MI-URR	MI AR-15 Upper Receiver Action Rod
Upper Receiver Action Rod, AR-10 (R)	The only way to properly secure your upper receiver while you install your barrel and muzzle device.	MI-308URR	MI AR-10 Upper Receiver Action Rod
Gas Tube Installation Block (r)	Installing the gas tube roll pin into the gas block and gas tube takes patience, a solid surface, and (if you don’t have one of these tools) 3 hands. Not absolutely essential, but very helpful.⁵	PENDING

1: The jaws of the vice block must be wide enough to accommodate the vice block. A 3″ jaw opening is sufficient for the vice block models that we recommend.

2: The Vism vice block works with the Aero Precision AR-10 (M5) platform. However, because the AR-10/LR308 platform is not standardized, lowers from some manufacturers may not be compatible.

3: Note that this tool is NOT COMPATIBLE WITH AR-10 components.

4: Note that this tool is NOT COMPATIBLE WITH AR-15 RECEIVERS.

5: We have tried a few gas block jigs and have yet to find any that fit a wide range of gas blocks without modification. We have exhausted our retail options, so we are getting ready to try out some options available on Etsy and will report back soon.

Tools We Didn’t Categorize (Other Installation Tools)

What It Is	Why You Need It	Part Number	PB Pick
Borescope	Visual alignment of gas port and gas block.	NTG200H	Teslong NTG200H Borescope
Gas System Illuminator	Use with borescope to visually align gas port and gas block.	GSIllum	Gas System Illuminator
Gas Block Alignment Tool, 0.750" (r¹)	Ensuring the gas block is properly aligned with the gas port in the barrel.¹ Use this if you are not using borescope for visual alignment.	GBG750	Gas Block Genie 0.750"
Pivot Pin Detent Tool, AR-15 (r²⋅³)	Installing the pivot pin spring and detent on an AR-9 or AR-15.²⋅³	AVAR15PPT	Real Avid AR-15 Pivot Pin Tool
Pivot Pin Detent Tool, AR-10 (r²⋅⁴)	Installing the pivot pin spring and detent on an AR-10.²⋅⁴ NOTE: This needs to be modified to work with Aero Precisiom M5 lowers.	AVAR10PPT	Real Avid AR-10 Pivot Pin Tool
Barrel Dimpling Jig (r³)	To properly install a set screw³ gas block onto a barrel. If you aren’t going to properly dimple your barrel or if you are going to use a clamp on gas block³, you don’t need this.	DJ7	SLR Barrel Dimpling Jig
Barrel Nut Alignment Tool (O)	If you are not using an Aero Precision Enhanced upper receiver (against our recommendation), you may want this tool. Or you can use your gas tube (don't damage it) or a #15 drill bit.	1100182	Wheeler Upper Receiver Action Rod
Gas Key Staking Jig (O⁴)	If you are building a bolt carrier group or have to replace the gas key, this tool makes staking/re-staking a lot easier.⁴	MOACKS2	Michiguns MOACKS II
Headspace Gauges (r)	Headspace of your barrel is really important. Too loose, and you get popped primers. Too tight, and your gun can explode. It is a good idea to check your headspace on a new barrel. These gauges fit the bill.	ForsterHG	Forster Headspace Gauges
Trigger Pull Gauge (O)	If you are interested in dialing in (or verifying) a particular trigger pull weight, one of these can help.	710904	Wheeler Digital Trigger Pull Gauge

1: Poor gas block alignment will cause cycling and reliability issues.

2: This tool is priceless. It will save you a lot on lost detents and eye surgery.

3: We do NOT recommend using clamp on gas blocks. They are too susceptible to shifting on the barrel, which will cause cycling issues.

3: Note that this tool is NOT COMPATIBLE WITH AR-10 components.

4: Note that this tool is NOT COMPATIBLE WITH AR-15 components.

Return to Build Considerations

Continue to Lock and Lube

Tools and Materials for Building an AR

Slick Stuff and Sticky Stuff (Lubrication and Thread Locker)

Tools For Leverage (Wrenches)

Tools You Twist (Drivers and Bits)

Tools You Whack (Punches)

Tools You Swing (Hammers and Mallets)

Tools That Hold Stuff (Blocks and Vices)

Tools We Didn’t Categorize (Other Installation Tools)

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